I'm not sure about the mortgages, etc.

But my mom is from the pelopennese. Her town is called Karitena, but that sounds too small from what you all want

Have you checked out the area around Sparta, or Kalamata? Kalamata has nice beaches. Also Akrata is nice too. My aunt house her house there, although she only visits it. She tends to stay in Athens for work.

Sorry I couldn't be of much help Good luck!